This invention relates to vibratory feeders for feeding small parts such, for example, as chip capacitors, transistor chips, or the like, in which the parts are oriented into a particular position and fed outwardly to a utilization device and any parts which are not properly oriented during the process, but remain misoriented, are rejected by the feeder and recirculated to the beginning for passing through the feeder and orienting process again. This process goes on continuously and as the parts are used at the output of the feeder, as by a pick and place machine, additional parts are added to the supply hopper, or inventory mechanism, so that the orienting and feeding can go on continually.
Recirculating feeders of the type described utilize some assymmetry or anomally in the shape of the device to be fed, such for example as rectangular as compared with square, to orient the devices into the proper attitude, rejecting those which do not conform to this attitude before the end of the feeder is reached, and feeding out the devices which are properly oriented.
Prior devices of this nature have been bulky and subject to jam ups because the orienting mechanisms did not function satisfactorily, would not orient a sufficient percentage of the devices in a single pass through the mechanism, thereby requiring excessive amounts of recirculation, and would also reject too high a percentage of devices which were properly oriented. Orienting and feeding semiconductive devices which are small parts, being of the order of small fractions of an inch on a side, require feeders of small size to be satisfactory. It is further required that the devices be accurately oriented so that automatic equipment may be used to pick them up and place them into another location without additional manual effort. Typical of prior devices for feeding and orienting articles is the U.S. Pat. No. 2,939,567 Mazura et al. In this patent, a part of a fastener, ordinarily referred to as a zipper, is oriented merely by vibrating the part against a rail along a relatively long surface. Such apparatus would have difficulty functioning with devices that are only slightly rectangular as compared with square because of insufficient mechanism for rejecting devices not properly oriented, and would not function with transistor chips, for example, which have terminals extending from two sides and lying below a major surface of the transistor chip.